This invention relates to the art of vermin traps and, more particularly, to an improved vermin trap of the character including a layer of tacky, thermoplastic, pressure sensitive adhesive to which the vermin stick upon coming into contact therewith.
Vermin traps have been provided heretofore by coating a tacky, thermoplastic, pressure sensitive adhesive onto a suitable support which is then positioned in an area where vermin tend to move so that when the vermin come into contact with the adhesive they are unable to extricate themselves, whereby they either die or can be killed and suitably disposed of. One such vermin trap especially for trapping larger vermin such as rats and mice is disclosed in copending patent application Ser. No. 338,621 filed Jan. 11, 1982 in which I am a co-inventor, and which application is a continuation of application Ser. No. 53,381 filed June 29, 1979, the disclosures of which are hereby incorporated herein by reference. The present invention relates to an improvement which will be described in detail hereinafter in connection with the vermin traps disclosed in the aforesaid copending application. However, as will become apparent hereinafter, the improvement is applicable to other vermin traps of the character using a tacky, thermoplastic, pressure sensitive adhesive and to the use of such adhesives having characteristics other than those particularly disclosed in the aforesaid copending application.
Vermin traps of the character to which the present invention is directed generally have been provided heretofore by placing a homogeneous layer of tacky, thermoplastic, pressure sensitive adhesive in a shallow tray-like receptacle into which small vermin crawl and onto which larger vermin such as rats and mice step when the trap is placed in an area of vermin activity. The adhesive material can be melted and poured into such a tray to form the tacky adhesive character upon cooling, as is disclosed in the aforementioned copending application, or the adhesive may be supplied in a tacky condition such as in a large container from which quantities are withdrawn and suitably spread into place in a container.
Such traps are extremely effective for very small vermin such as insects and spiders and, in most instances, are extremely effective for trapping larger vermin such as mice and rats. In connection with trapping vermin of the latter character, however, effectiveness of the trap depends to some extent on the size or weight and strength of the vermin as well as to the extent of contact made by the vermin with the pressure sensitive adhesive. More particularly in this respect, it will be appreciated that trapping of the vermin requires sufficient contact and penetration of the pressure sensitive adhesive to avoid the vermin being able to extricate itself from such contact. While the pressure sensitive adhesive is tacky and somewhat soft, the homogeneous nature thereof heretofore has resulted in vermin escapes as a result of inadequate penetration necessary to preclude or minimize the vermin's capability to extricate itself. When it is considered that such adhesive-type traps used in highly vermin infested areas such as zoos can result in the destruction of several thousand rats and mice over a period of a few months, it will be appreciated that it becomes very desirable to either increase the number of vermin trapped over a given period of time or to reduce the time required to destroy a given number of vermin by minimizing such escapes.